Typewriting machine



May 14, 1929. A. G. KUPETZ TYPEWRITING MACIjINE Filed Aug. 25. 1925 i Il Patented May 14, 192.9.

ADOLYPH G. KUPETZ, 035 NEW YORK, N. Y., A.

SFSIGNOR TO UNDERWUOID ELLIOTT FISHER COMPANY, OF NEW YGRK, N. Y., ACORPORATION OF DELAWARE.

TYPEWRITING MACHINE.

Application filed August 25, 1925. Serial No. 52,271.

This invention relates to line-spacing mechanism for typewritingmachines, and has particular reference to the provision of theprevention of overthrow of the platen.

The line-spacing mechanism in standard llnderwood typewriting machinesincludes a ratchet rotatable with the platen and operated by a pawlpivoted upon a slide on the platen-frame. The slide is actuated by aline space lever, and is limited in its linespacing movei'nent by theengagement of the pawl with an overthrow-prevention stop. Such devicesare subjected to rather hard usage, particularly in that type of machinein whiclrthe carriage-return and the line spacing of the. platen areaccomplished by the use of an electric motor. lilxcessive strain on theover throwprevention stop soon renders the stop inetlective toaccurately determine a line-space distance, and there after causes theplaten to overthrow its norreal line'space stop position.

l he present invention aims to relieve all strain, incident to a violentmovement of the line-spacing lever, from the line-space pawl and theline-space wheel. This is done by providing that the line-space slidemay be arrested at the end of a line-spacing stroke through abutmentwiththe carriage-frame, while a second or auxiliary stop becomes operativeindependently of the first stop, to prevent overthrow of the platenbeyond the line-spaced position determined by the slide, Hence thestress developed. through the coaction of the line-space pawl and linespace wheel is due to the momentum of the line spaced platen, and notfrom the violent manipulation of the line-space lever and the momentumof the hand and arm of the operater, or of other driving means.

These objects are accomplished by the provision of a permanent stopmounted on the platendirame and engageable by the linespace slide,whereby movement of the slide will be arrested at the end of itslinespacing movement and without conveying any stress to theoverthiowprevention stop. In this manner, the overthrow-prevention stopis relieved of the shock incident to a sudden or violent manipulation ofthe line-spacing lever.

Other features and advantages will here of a typewriting invention. t

Figure 2 is a fragmentary front elevation with parts in. section. 1

Figure 3 is a detailfront elevation of one end oi": the platen-frame.

F' me i is a sectional View on the line l l; of Figure 2.

Figure Tris aview similar to Figure 1, showing the linespace slide movedinwardly to the limit of its possible movement.

, Figure 6 is a fragmentary top plan view of the device.

A platen 10 is fixed upon a shaft 11 lior rotation in the ends 12 of aplatendirame supported by the usual carriage 13. A trans versely movableslide 14E is mounted in one end of the platendrame, and has pivoted, asat 15, a pawl 16 which engages a rah-hot 17 rotatable with the platen10. The ratchet 17 is engaged by the usual roller detent 17 to maintainthe platen in proper s aced position when the pawl becomes disengagedfrom the ratchet. Carried by a rearward extension 18 of the slide 14 isa pin 19, which is loosely engaged by an arm 20 01 a vertical rock-shaft21. The shaft 21 is supported at its bottom end in a bracket 22 andconnected to the usual power-driven carriage return and line-spacingmechanism, of H. L. Pitman, patented April 13, 1926, No. 1,580,326, anddesignated generally by the character 23. A coil spring 24.- has one ofits ends semired to the extension 18 ot the slide 14, while its otherend is attached to one 01. the end members of the platenl'rame, wherebythe slide 14: and its associated parts will maintain a normal. position,as illustrated-in Figure 1.

A nose member 25, carried by the pawl 16 and having anangularly-disposed rear edge 26, co-operates with anoverthrow-prevention stop 27 to prevent the ratchet and platen fromrunning beyond their proper positions after the line-space slide 14 hasbeen shifted. The stop member 27 is placed immediately beyond therearward limit of the edge 26, so that it will not actually be engagedexcept in the event that the platen and ratchet start to overthrow.

In order to limit the rearward movement of the slide 14, and thusrelieve the overthrow prevention stop of shock, incident to machineembodying the the line-spacing operation, the forward end of the slideis offset as at 28. A stop memmanner.

ber 29 is mounted upon the carriage 13 in the path of movementof thoffset 28. This stop member is here shown as being mounted with thecarriage-shift lock 30, but itmay, of'course, be attached in any othersuitable The forward end of the platenframe 12 may have a suitablereinforcement as at31 to increase the'meehanical strength of theseparts.

The slide 14 may be actuated by a line spacing lever 32, which may bemanually operated orotherwise, and, when the offset 28 abuts the stopmember 29, further rearward movement is prevented. In the event that thelever 32 is'shifted violently, so that the platen l0 and ratchet l7 tendto overrun,

the engaging tooth of the ratchetwill, by a cam action, raise the pawl16 about its pivot 15, whereupon the inclined edge 26 of the pawl nosewill contact with theoverthrowprevention stop 27 and prevent 'furtherupand pawl is arrested at the line-spaced position by a positive stop onthe frame; that the line-space pawl, per se, loses control of the platenand line-space wheel beyond the l shock incident to arresting theline-space slide; and that the other stop checks the overthrow of theplaten without excessive strain upon the eoacting parts.

Variations may be resorted to within the scope of the invention, andportions of the improvements may be used without others.

Having thus described my invention, I claim:

In a typewriting machine, the combination with a rotatable platen and aline-space wheel, of a line-space slide provided with an integral stopthereon, a mani1ally-o1 )erable line-space lever adapted to engage saidstop to move said slide, said stop also serving in operated position asa limit stop for said slide, a pawl pivoted on said slide and engageablewith the line-space wheel to retate the platen, and means independent ofsaid stop to limit the rotary movement of the platen beyond theline-space position.

ADOLPH Gr. KUPETZ.

